#include<iostream>
#include<algorithm>

using namespace std;
#define int long long

const int N = 2e5 + 10;
int a[N];
int n , c;
signed main()
{
    cin >> n >> c;
    for(int i = 1;i <= n;i ++) cin >> a[i];
    sort(a + 1 , a + 1 + n);
    int ret = 0;
    for(int i = 2;i <= n;i ++)
    {
        int b = a[i] - c;
        ret += (upper_bound(a + 1 , a + i , b) - lower_bound(a + 1 , a + i , b));
    }
    cout << ret << endl;
    return 0;
}